Machine for hardening hacksaws.



c. L. ERICSON.

MACHINE FOR HARDENING HACKSAWS.

Patented Aug. 17, 1915.

- APPLICATION FILED MAR. 22, 1915. 1,150,51 1

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c. L. ERICSON. MACHINE FOR HARDENING HACKSAWS.

APPLICATION FILED MAR. 22. 1915. 1,1 50,51 1 Patented A11 17, 1915.

3 SHEETS-SHEET 2.

INVENTOR.

ATTORNEY5.-

C. L. ERICSON.

MACHINE FOR HARDENING HA CKSAWS.

APPLICATION FILED-MAR. 22. 1915.

1,150,51 1 Patented Aug. 17,1915.

3 SHEETS-SHEET 3.

Fun. 7- 6/ E 11 W- WITNESSES: INVENTOR. %M 7 M94.

A TTORNE Y8 "UNlTEE @TATF% PATENT @FFlfifi.

CARL L. ERICSON', OF SPRINGFIELD, MASSACHUSETTS, ASSIG'NOR TO AMERICAN SA'W' AND MANUFACTURING COMPANY, OF SPRINGFIELD, MASSACHUSETTS, A CORPORA- TION OF MASSACHUSETTS.

Application filed March 22, 1915.

To all whom it may concern:

Be it known that I, CARL L. ERIOSON, a subject of the King of Sweden, and a resident of Springfield, in the county of Hampden and State of Massachusetts, have invented a new and useful Machine for Hardening Hacksaws, of which the following 1s a specification.

My invention relates to improvements in the art of hardening thin steel implements and more particularly hack-saws, and especially to machines for such purposes, and consists of a heating medium, certain peculiar mechanism for supporting, guiding, and actuating l1acksaws, when connected end to end in chain formation, through said heating medium, means to apply a hardening medium to said saws when they leave said heating medium, and means to prevent such hardening medium from following along the saws to said gether with such auxiliary and subsidiary parts and members as may be needed or desired in order to complete the machine in all its details.

The primary object of my invention is to produce a comparatively simple, yet'highly eflicient and practicable, machine for expeditiously, economically, and uniformly har dening hack-saws, or other implements, articles, or objects that the machine may be capable of handling.

Another object is to provide such a machine with means for overcoming any tendency on the part of the saws to twist or warp out of shape during the hardening process.

A further object is to afford means in said machine to prevent the hardening medium from running on the saws into the heating medium.

Other objects and advantages will appear in the course of the following description.

A preferred form or embodiment of the invention, whereby I attain the objects and secure the advantages of the same, is illustrated in the accompanying drawings, and I will proceed to describe the invention with reference to said drawings, although it is to be understood that the form, construction,

Specification of Letters Patent.

heating medium, to-' Patented Aug. 17, 1915.

Serial No. 16,243.

arrangement, etc., of the parts in various as 'pects are not material and may be modified without departure from the vention.

In the drawings, in which like numerals designate like parts throughoutthe several views, Figure 1 is a top plan of the machine as aforesaid, the middle portions of the bed frame and furnace and a similar portion of the supporting guide members at the front end being broken out to economize space; Fig. 2, a front side elevation of said machine as shown in the preceding view; Fig. 3, an enlarged cross-section through the supporting guide at the front end, taken on lines 3-3, in Fig. 1; Fig. 4:, a longitudinal vertical section through said machine taken directly in front of the feed rolls, the middle portions of the bed frame and furnace being broken out as before, and only the parts of the front-end supporting guide and members that are attached to said frame appearing; Fig. 5, an enlarged sectionaldetail showing one of the adjustable lateral guides; Fig. 6, an edge elevation of a short length of a chain of saws,withfthe leader or follower connected therewith; Fig. 7 an enlarged front-end elevation, in partial sec tion, of the machine, on lines 7-7, looking in the direction of the associated arrow, in Fig. 1; Fig. 8 an enlarged backside elevation of the drag or brake provided for the feed rolls; Fig. 9, an enlarged cross-section of the furnace, and, Fig. 10, an enlarged backside elevation of the feeding mechanism at the rear end of the machine.

Although this machine is designed especially for handlinghack-saw blades, hereinafter referred to simply as saws or blades, while such saws or blades are being hardened, it is to be understood that said machine may be employed to handle any other objects for which it is found to be adapted, as hereinbefore intimated, wherefore I do not intend to restrict the use of the machine to hardening saws exclusively, and the term saw or blade is to be accepted as meaning anything that can be successfully hardened in my machine.

spirit of the in- The objects to be hardened in this machine must first be connected end to end to form a continuous line, string or chain. This chain may be indefinitely added to at the unhardened terminal, and substracted from, so to speak, at the hardened terminal, hence any number of objects can be handled in one uninterrupted operation. A short length of chain is illustrated in Fig. 6, such chain consisting of a plurality of blades 1 and a plurality of connecting links 2. The links 2 pass through the openings common to blades of the hack-saw type. The links 2 afford convenient means for easily and quickly connecting the blades 1 at one end of the chain and disconnecting them at the other end. rod 4 is also shown in this View, such rod having a hook 5 at one end to engage either the leading end of the foremost blade 1, as shown, when said rod becomes a leader, or to engage the tail end of the last blade, when said rod becomes a follower. The service performed by the rod tin either capacity will subsequently be explained. The blades 1 travel flatwise through the machine, as will presently appear.

Passing now to the machine, it will be observed that the same comprises a horizontal bed frame 6 supported on legs 8, such frame being of any suitable and approved construction, a front-end supporting guide 10, three sets or pairs of feed rolls 11, the rolls in each pair being arranged one above and the other below, supporting guides 12, lateral guides 13, a furnace 1 1, a pipe 15 to supply the hardening agent or medium, oil being the best-known medium of the kind, an air pipe 16, a gear-pump 17 for the oil, a blower 18 for the air, and the necessary driving mechanism.

The supporting guide 10 is a horizontal member carried on the upright part of a frame bracket 19 and the top of a floor post 20, and steadied or stayed by two oblique lateral braces 21. The bracket 19 is bolted to the top of the bed frame 6 near the front end of the latter, and the braces 21 extend between said front end of the frame and the top of the post 20. There is a longitudinal channel 22 in the top of the guide 10, such channel being provided to re ceive the blades 1 flatwise; and there is a longitudinal groove 23 in the bottom of said channel to accommodate the parts of the links 2 that extend below the under side of said blades. The floor of the channel 22 and the tops of the under rolls 11 and of the supporting guides 12 areall on the same level, said guides also being horizontal members arranged in line with the guide 10. The rear end of the guide 10 is adjacent to the front or first pair of rolls 1]..

The first pair of feed rolls 11 is at the front end of the frame 6, as just intimated, While the second and third pairs of feed rolls 11 are at the back end of said frame. Three brackets 24 are secured to the frame 6 to afford supports for the rolls 11. The latter are mounted on shafts 25 and secured thereto, and the three lower shafts 25 are journaled in fixed bearings 26 which are bolted to the upright parts of the brackets 21. The three upper shafts 25 are journaled insliding bearings 27. The bearings 27 are arranged to slide vertically on the upright parts of the brackets 24 above the bearings 26. The upper rolls 11 are forcibly but yieldingly held down on the under rolls 11, or on intervening elements, by means of springs 28 which are interposed between the horizontal parts of the bearings 27 and screws 29 tapped into fixed arms 30 that project from-the-tops of the brackets 27 over said horizontal bearing parts. The tension of the springs 28 is increased or decreased accordingly as the screws 29 are turned down or up in the'arms 30, and in this man ner and by this means the force which the upper rolls 11 exert is regulated, being increased or decreased at will.

All of the guide members extend longitudinally of the machine, in the same vertical plane, and the rolls 11 are in the same plane, but by preference the shafts 25 are deflected a little from a right-angular relation to such plane, for the purpose of throwing said rolls into a slight angular relation to said plane and the path which the chain takes in pass ing through the machine. The purpose of this is so that the rolls 11 will urge the saws 1, as they are actuated by and pass between said rolls, toward one sideof the path of travel, or against the guides 13, in the present case. Thus lateral guiding means on one side only is required, which is especially to be desired with objects having teeth on one edge. The rolls 11 are set to force the saws toward the front side of the machine, as well as to actuate them toward the rear end thereof, wherefore, if said saws be properly placed with their teeth toward the back side of the machine, the plain longitudinaledges or backs of said saws will bear and ride against the guide members located in front, no other lateral guide members being needed.

There are intermeshing gears 31 secured on the shafts 25 for each pair of rolls 11,

and an intermediate gear 32 mounted on a stud 33 which is set in a box 34 secured to the upright of the second bracket 24, said intermediate gear intermeshing with the gears 31 on the shafts that carry the under rolls in the second and third pairs. The lower shaft 25, at the front end of the machine, is extended beyond the back end of its bearing 26, and a sprocketavheel 35 and a brake wheel 36 (Fig. 8) are secured on this protruding part of said shaft. An arm 37 rises from the back side of the frame 6 and is provided at the top with a friction brake or clamp 38. The clamp 38 fits around the wheel 36 and prevents backlash on the part of the driving mechanism for the feed rolls. The lower inner shaft 25, at the rear end of the machine, or the shaft for the lower roll 11 in the second pair, is extended beyond the back end of its bearing 26, and a sprocket wheel 39 is secured on this protruding part of said shaft. J ournaled in a bearing bracket 40, which depends from the back side of the frame 6, in a vertical plane that is central to the vertical planes of the axes of the sprocket-wheels 35 and 39, is a shaft 41, and secured on said shaft are two sprocket-wheels 42 and a driving pulley 43. Sprocket-chains 4444 connect the sprocketwheels 42 with the sprocket-wheels 35 and 39. Power applied to the pulley 43 drives the rolls 11 in the directions necessary to actuate the chain of saws through the machine from the front end to the back end of the same, through the medium of the shaft 41, the sprocket-wheels 42, the sprocketchains 44, thesprocket-wheels 35 and 39, the gears 31 and 32, and the shafts 25. The sprocket-wheel 39 should be a little smaller than the sprocket-wheel 35, in order that the speed of the feed rolls at the back end may be accelerated. The speed of said back-end feed rolls should be accelerated to the extent necessary to compensate for the portion of the chain which is expanded and so lengthened by the heat in the furnace 14, and in order to keep said chain taut during its passage through the machine, otherwise the saws would be liable to twist and warp out of shape. The actuating mechanism thus puts a tension on the chain and serves a double purpose.

The difference insize between the sprocketwheels 35 and 39 is so comparatively slight as not to appear in the drawings, while the deflection of the shafts 25 is so inconspicuous as scarcely to show even in the full size machine, to say nothing of the drawings, but the angularity of the feed rolls, relative to the path of the chain and which is produced by such deflection, and the corresponding angularity of the rotary members associated with said rolls, at the front end of the machine, are illustrated in an exaggerated manner in Fig. 7. A similar condition prevails at the rear end of the machine. The path of the chain, referred to above, is parallel with the sides of the frame 6.

The rolls 11 have grooved peripheries to permit the links 2 to pass freely between said rolls and permit the latter to grasp the saws 1.

The supporting guides 12 are carried on the uprights of two brackets 45 which are mounted on the frame 6, one of said guides being located directly behind the lower roll 11 of the first pair, and the other being located directly in front of the lower roll 11 in the second pair. Each guide 12 has a longitudinal groove 58 therein to accommodate the under parts of'the links 2. At the front end of the rear guide 12 is a trough 46. The floor of the trough 46 opens at 47 into a pipe 48 under said trough. Below the pipe 48 is an oil tank 49 into which said pipe opens.

The gear pump 17 and the blower 18, which are at the rear end of the machine and below the frame 6, may be mounted on a support 50, and said support in turn mounted on the tank 49. In the present case a single shaft 51 is provided to drive both the pump and the blower, such shaft having its ends journaled in brackets 52-52 which depend from the sides of the frame 6. The shaft 51 is driven by a pulley 53 secured thereon,-and a belt 54.

A pipe 55 connects the pump 17 with the tank 49 or with the oil in said tank, and, when in operation, said pump raises oil from said tank through said pipe and discharges the same through the pipe 15. The pipe 15 branches to provide two points of discharge or outlets 56, one above the other, such outlets being at the open front end of the trough 46 and directed toward such end. Provision is thus made for discharging oil, the hardening agent, on both the top and bottom of the blades 1 as they enter the trough 46, the arrangement of parts being such that said blades pass between the outlets 56 just before entering said trough. The oil that enters the trough 46 escapes through the opening into the pipe 48 and returns to the tank 49.

The air pipe 16, which extends upward from the blower 18, is carried over to locate its point of discharge or outlet, represented at 57, immediately in front of the upper oil outlet 56, such outlet like the oil. outlets, being directed backward toward the open end of the trough 46. Some of the oil discharged onto the top of the saws 1 would ordinarily be liable to follow along said saws toward the furnace 14, behind which latter are situated the oil outlets 56, and if the oil thus escaping should get into said furnace it would become ignited and cause trouble, but the air, forced by the blower 18 through the pipe 16 and out on to the tops of the saws, blows the oil on said saws forward, that is, forward in the direction of travel of the saws, into the trough 46, from whence the oil escapes into the tank 49, as already explained. There is, therefore, no danger from this source.

The lateral guides 13 are located adjacent to the front sides of the rolls 11 and of the guides 12, and are preferably adjustable laterally so that they may be set to receive blades of different widths. These are the members against which the backs of the blades are forced by the lateral action produced by the feed rolls, and against which .said backs ride as said blades are actuated hardened steel inserts 59 to afford wearing surfaces to receive said blade backs. Each guide 13 is secured to the inner end of a slide 60 which is mounted on the horizontal part of an angular bracket 61. Each bracket 61 is securely bolted to the front side of the frame 6 and extends upward and over to the vicinity of or adjacent to the front vertical plane of the rolls 11. Having special reference toFig. 5, it will be observed that there is a longitudinal slot 62 in the slide 60, through which a vertical bolt 63 passes into threaded engagement with the horizontal part of the bracket 61, and a horizontal screw 64- which is tapped into said bracket in parallel relationship to said slide, is arranged to turn freely or loosely in an opening in a lip or lug 65 that depends from the outer end of said slide, and has thereon a collar 66, between which and the head of said screw said lug is received. It is now clear that, when the bolt 63 is loosened, the slide 60 with the guide 13 carried thereby may be actuated either inwardly or outwardly by turning the screw 6% in one direction or the other, since said screw has no independent longitudinal movement relative to said slide, owing to the fact that the lug 65 is held between the collap 66 and the screw head. After adjustment the bolt 63 is retightened. The mountings for both guides 13 are alike, and adjustment is effected in a similar manner in each case. I

The furnace 14- is located in the path of the chain, between the inner ends of the guides 12, but somewhat remote from such ends. Two cross bars 67 are secured to the top of the frame 6 to support the furnace 1 1 and a pair of gas burners 68 which constitute parts of said furnace. The fuel is supplied to the burners 68 through tubes 69 which are connected with said burners at one end. The furnace is made up of inclined side walls and a top piece supported from the cross bars 67 by brackets 70, and has a central partition 71 which separates the two burners and rises to a plane th. t is a little below the plane of the path of the chain. The ends of the furnace are open, and the chain course is through said furnace just above the partition 71. The furnace is also open beneath and at the sides of the burners 68 so as to allow an abundance of air to reach said burners.

Each bearing for each shaft 25 is provided with an oil-supply tube 72. The friction member 38 may be loosened or tightened on the brake wheel 36 by means of a thumbscrew 7 3. This friction device is of old and well-known construction; so, also, are the gas burners 68.

When the machine is in operation, gas is admitted through the tubes 69 to the burners 68, where it burns and heats the furnace 14:, the heat therein rising both sides of the partition 71 and coming into contact with the blades as they travel through said furnace over the top of said partition. The blades are thus heated and, upon emerging from said furnace, pass between the outlets 56 and are quenched by the oil discharged from said outlets. This completes the hardening of the blades, and there remains nothing further to be done to them except pass them out of the machine and detach them from the chain.

Having described the machine construction and explained the functions and operations of the parts and mechanisms, 1 will now proceed to explain the operation of the machine as awhole, it being assumed that a plurality of blades 1 has been formed into a chain by linking together said blades, and the leader or rod 1 attachedto the foremost or leading blade in said chain; and it being assumed further that all needed adjustments have been attended to, the gas at-the burners 68 has been ignited, and the machine, including the gear pump 17 and the blower 18, started. 7

In the first place the chain is laid on the supporting guide 10 flatwise and with the plain edges or backs of the blades 1 toward the front side of said guide, the rod 4: is passed between the first set of feed rolls 11, carried through the furnace 1 1, and passed through the second and third sets of feed rolls, and by means of said rod the leading or attached terminal portion of said chain is drawn into the grasp of saidfirst set of rolls, through said furnace, and into the grasp of said second and third sets of rolls, when said rod is detached. The chain is now supported underneath by the guide 10 and the guides 12, and is advanced and at the same time forced against the guides 13 by the rolls 11. The blades 1 in advancing move in the channel 22 and on the floor of the same, and on the guides 12, while the underneath portions of the links 2 move in r the grooves 23 and 58, and both the upper and under portions of said links pass freely between the rolls 11 in each pair. That portion or reach of the chainthat is between the front and rear sets of feed rolls is held tight by said rolls, so that said reach although expanded by the heat of the furnace 1st through which it passes, does not sag between the adjacent or inner ends of the front guide 12 and the trough 16, but takes a straight course through said furnace. The aforesaid reach being kept tight, there is no opportunity for the blades to get out of shape. As the chain passes through the machine, each blade is first subjected to the heat in the furnace 14, and then treated with the oil, the latter being pumped onto both sides of said blade as the latter enters the trough 46. The blast of air from the pipe 16 forces the oil that lodges on the blades, or so much of such oil as has a tendency to follow along said blades toward the furnace 14:, or might have such a tendency, into the trough 4:6. The oil-forced into the trough 46 by the air blast and that which is carried in on the blades escapes from said trough into the tank, as already explained. The blades are successively heated and pro gressively and successively quenched, the operation and result being uniform. At the end of the hardening operation, that is, when all of the blades have been hardened, or it is not desired to treat any more, the power is shut off from the pulleys 43 and 53 and the burner flames are extinguished. If all the blades in a given length of chain are to be tempered, the rod 4: is hooked on to the tail end of said chain and the last blades are supported under tension thereby, after they leave the first pair of feed rolls and until they reach the feed rolls at the rear end of the frame.

From the foregoing it is seen that the machine when in operation turns out a continuous line of hardened blades, and that the capacity of said machine for so doing is practically unlimited, inasmuch as thehardening operation may be continued as long as the linked blades are fed into the machine, the supporting and guiding, feeding, heating, and quenching means all being capable of handling and acting on a limitless member of blades.

The method of hardening involved in this invention is made the subject of a separate application, filed on even date herewith and serially numbered 16242.

lVhat I claim as my invention, and desire to secure by Letters Patent, is

1. The combination, with heating means, quenching means, feed rolls in front of said heating means, and feed rolls behind said quenching means, of a plurality of objects to be hardened, such objects having perforations adjacent to their ends, links engaging the perforated parts of such objects to form a chain, and a hooked rod adapted to be inserted in the perforation at either end of such chain, to support such end while the same is unsupported by the feed rolls.

2. In a machine of the class described, lateral guiding means for a chain of objects to be hardened, and means to actuate such chain longitudinally and cause it to bear against said guiding means.

3. In a machine of the class described, bottom guides and lateral guides for a chain of objects to be hardened, and means to actuate such chain longitudinally, such actuating means being adapted to urge said chain against said lateral guides.

4:. In a machine of the class described, heating means, quenching means, means to actuate a chain of objects, to be hardened, through said heating means and said quenching means, means to impart a lateral thrust to said chain in its travel, and means to receive such lateral thrust and guide said chain on that side.

5. The combination, in a machine of the class described, with a furnace, means to actuate a chain of objects through such furnace, and means to apply a hardening medium to said chain upon emerging from said furnace, of means to prevent such medium from following along said chain to said furnace.

6. The combination, in a machine of the class described, with a furnace, means to actuate a chain of objects, to be hardened, through said furnace, and means to apply a hardening medium to said chain upon emerging from said furnace, of means to apply air under pressure to said chain to prevent said hardening medium from following along said chain to said furnace.

7. The combination, in a machine of the class described, with suitably mounted feed rolls, and supporting means for a chain of objects actuated by said rolls, the latter being set in angular relation to the direct course over said supporting means, and tending to divert said objects from said course, of lateral guide means for said objects, whereby the latter are held to said course.

8. The combination, in a machine of the class described, with suitably mounted feed rolls, and supporting means for a chain of objects actuated by said rolls, the latter being set in angular relation to the direct course over aid supporting means, and tending to divert said objects from said course, of lateral guide means for said objects, whereby the latter are held to said course, and means to adjust said lateral guide means to accommodate objects of different widths.

9. The combination, in a machine of the class described, with means to actuate a chain of objects in an approximately straight path, of a furnace in such path, means to discharge oil into such path, and means to blow air into such path between said furnace and the point of entrance to the path of the oil.

10. The combination, in a machine of the class described, with means to actuate a plurality of loosely connected objects in an approximately straight path, and a trough having an oil exit, such trough being in such path, of a furnace in such path, and means to discharge oil onto said objects after they leave said furnace and as they are about to enter said trough.

11. The combination, in a machine of the class described, with means to actuate a chain of objects in an approximately straight path, and a trough having an oil exit, such trough being in such path, of a furnace in such path, means to discharge oil onto said objects after they leave said furnace and as they are about to enter said trough, and means to blow air onto said objects in such a manner as to prevent the oil 10 discharged thereon from flowing toward said furnace.

CARL L. ERICSON.

Witnesses:

F. A. CUTTER,

C. CY. DAVIS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. G. 

